Gothenburg is a port city between Oslo and Copenhagen and is Sweden’s second largest city with approximately 550,000 inhabitants. Gothenburg is home to a variety of strong industries including VOLVO, Volvo Cars and SKF. Gothenburg will face a big transformation as the city’s population is expected to increase to 700,000 within the next 20 years. During the same period 25,000 new apartments will be built and 50,000 new jobs will be added.
Gothenburg wants to understand how AVs can be used to create a sustainable, attractive city and there are many activities related to AVs going on in the city. For instance, in the Drive Me project, the city is working with Volvo Cars and five more stakeholders to pilot fully autonomous (Level 4) cars with 100 normal commuters, on public roads.
CoEXist use cases in Gothenburg
Gothenburg has varying designs of urban space, so the city administration wants to understand how CAVs can be accommodated in these types of areas.
The first use case site is located in the city-centre of Gothenburg. It is a shared-space area with a high pedestrian modal share and the presence of other types of road users: cyclists, cars and urban freight vehicles.
The use case is focused on determining the traffic effects on shared spaces when an automated last mile service is introduced. A shared space environment may be problematic for CAVs to operate without significant delays due to the large volumes of pedestrians and cyclists as well as the lack of traffic control. In addition to the microsimulation tool Vissim, this use case utilises the “Viswalk” application to better represent the movement of pedestrians. The evaluated scenario is the introduction of an automated last mile service passing through the shared space to assess how advanced automation technology is required for such a service to be feasible from a traffic performance perspective.
One of the main takeaways is the fact that CAVs will take longer to cross shared spaces, due to their passiveness in comparison with a conventional car. This has significant influences once a zebra crossing is added to the simulation, which resulted in a traffic breakdown, as pedestrian flows hindered or even stopped the traffic flows of the passive CAVs. On the other hand, pedestrians hardly experience any difference at all with regards to the traffic performance metrics, as they are always given right of way.
Accessibility during long-term construction works
CoExist also took a closer look at the macro-level traffic flows in Gothenburg and the surrounding region. There are several construction projects in the central part of the city which will last for several years. The city of Gothenburg has the ambition to decrease the negative traffic effects of the long-term construction works, especially accessibility to the city centre.
Long-term construction is a common issue in cities and puts a lot of stress on the traffic system. It is therefore important to ensure that the introduction of AVs does not lead to further negative effects. The use case also investigates which measures can improve traffic during extended construction periods.
Depending on the CAV penetration rate, bidirectional traffic and other capacity supporting measures in tunnels could be possible. In this sense, two measures have been tested: a two-way AV-only tunnel tube for the Göta Tunnel; and reserved bus and AV lane on the major motorway network.
- For the model of the two-way AV-only tunnel tube, CoExist observed a slight decrease in travel time and delay for medium levels of automation, as well as larger effects once CAVs have reached high automation levels. Conventional vehicles also see improved traffic performance due to shift of AVs from alternative routes to the tunnel, thus freeing capacity on the network.
- Concerning the reserved bus and AV-lane on the major motorway network, direct positive results during low levels of automation are recognised for bus performance. AVs do not benefit from the effect, since the number of AVs increases and so does the use of the prioritised lanes.